Safety appliance for power-presses and like machines



W. WOELFEL.

SAFETY APPLIANCE FOR POWER .PRESSES AND LIKE MACHINES.

APPLICATION FILED JULY 16. 1918.

1,331,551 Patented 1 0103 11920.

3 SHEEN-SHEET l.

SAFETY APPU F0 W. WOELFEL A R POWER PRESSES AND LIKE ICATION man JULY 16, 191B.

MACHINES.

Paten Feb. 24,

W. WOELFEL.

I SAFETY APPLIANCE FOB POWER PRESSES AND LIKE MACHINES.

APPLICATION FILED JULY 16. IQIB.

Patented Feb. 24,1920.

3 SHEE1SSHEEI 3.

A9 a lfjjz jjitlie ZZia Zfel WILLIAM WOELFEL, OF PE ABODY, MASSACHUSETTS.

SAFETY APPLIANCE FOR POWER-PRESSES AND LIKE MACHINES.

Specification of Letters Patent.

Patented Feb. 24, 1920.

Application filed July 16, 1918. Serial No. 245,247.

To all whom it may concern Be it lmown that I, WILLIAM \VOELFEL, subject of the Emperor of Austria, and resident of Peabody, in the county of Essex and State of Massachusetts, have invented new and useful Improvements in Safety Appliances for PowerPresses and like Machines, of which the following is a specification.

This invention relates to a safety appli-.

ance for machines having parts moving to and from each other and more particularly to a safety appliance for power presses having two parts moving alternately to and from each other to press, stamp, emboss, or otherwise operate upon material inserted be tween the presser parts of the machine.

The principal objects of the invention are to provide safety appliances which will effectually guard a space between the parts of a machine moving to and from each other, which can be readily applied to various types of machines, and which is actuated by the moving parts of the machine and preferably by the parts of the machine which move to and from each other to emboss, stamp, or otherwise operate upon stock inserted between the parts, so that the operation of the appliance is automatic and positive. Another object of the invention is to provide a safety appliance which is yielding in action so that if it strikes the hand or arm of the operator before the operator has withdrawn his hand from between the parts of the machine its motion will be arrested and the operator will be given opportunity to withdraw his hand before the guard moves into its guarding position, the light yielding impact of the guard on the operators arm or hand serving as a warning to the operator. Another object is to provide guards at two or more sides of the machine as for example at the front and back and to join the two guards together in such manner that they may be moved into and out of guarding position in .synchronism by a single controlling means. Another object is to provide means for actuating the guard or guards which is controlled by one of the moving parts of the press or other machine to which the guard is applied and which is responsive to a small movement of the moving part of the machine to close the guard or guards.

Still other objects of the invention will be apparent from the following description and accompanying drawings in which Figure 1 is a front elevation of a power press with one embodiment of my invention applied thereto;

Fig. 2 is a top plan view of Fig. 1;

Fig. 3 is a side elevation of a portion of the machine viewed from the right of Figs. 1 and 2;

Fig. 4 is a side elevation of a detail of the machine viewed from the left of Figs. 1 and 2;

Fig. 5 is a vertical, longitudinal section on line 55 of Fig. 1

Fig. 6 is a View similar to Fig.6 showing the parts in a different position; and

Fig. 7 is a section on line 77 of Fig. 1.

The machine which I have chosen for the purpose of illustrating the preferred em bodiment of my invention is an embossing machine of a well known type comprising a stationary part 1 mounted on four corner posts 2, 3, 4 and 5 and a movable part 6 arranged to be vertically reciprocated on the corner posts 2, 3, 4 and 5 by power mechanism not shown. When a machine of this character is employed as an embossing ma chine the parts 1 and' 6 carry embossing platens on their opposing faces and the leather or other material to be embossed is inserted in the space 7 when the parts 1 and 6 are separated and when the part 6 is forced upwardly against the part 1 the sheet of leather in the space 7 is compressed between the embossing platens. The greatest danger to the operator from a machine of this character is the danger of getting his hand caught in the space 7 between the parts 1 and 6 of the machine as they move together;

. My improved appliance which is particularly designed to guard a space such as space 7 in a machine of the character described, comprises two gates 8 and 9 fast to shafts 10 and 11 respectively, the shafts l0 and 1.1 being journaled in brackets 13, 14, 15 and 16 at the four corners of the machine so that the shafts extend along-the front and rear sides of the machine somewhat above the space 7 so that the gates 8 and 9 cover the space 7 when they hang downwardly from the shafts 10 and 11 as shown in full line position in Fig. 3 and so that they uncover the space 7 when they are swung upwardly into horizontal position as shown by dotted lines in Fig. 3. The gates are connected together at the right hand side of the machine (Figs. 1 and 2) by a link 17 pivotally connecting at its oposite ends with arms 18 and 19 fast to the ends of shafts and 11 so that gates 8 and 9 are constrained to move into and out end of'arm 50 by a short link 53, the links of guarding position simultaneously.

The mechanlsm for operating the gates 8 and 9 is comprised as follows: A collar 20 is secured to the shaft 10 within the bracket carryin on its inner face a plurality 13 by means of a set-screw 21 and is provided with two projections 22 and 23. At the left hand side of collar 20 (Figs. 1, 2 and 7) is a disk 2e having its peripheral face spirally cut so as to provide. an offset shoulder or catch at 25, the disk being fastened to the shaft 10 by means of a key 26. Mounted in the top 27 of the bracket 13 is a plunger 28 adapted to cooperate with the disk 24.- to hold it in the position shown in Fig. 5 with the lower end 29 of the plunger 28, which constitutes a detent engaging the shoulder 25 on the disk 2%. The plunger 28 is rcciprocatably mounted in a sleeve 30 threaded into the top of the bracket 13 and is yieldingly urged downwardly by a compression spring 31 extending between a shoulder on the plunger and the cap 32 threaded upon the upper end of the sleeve 30. The sleeve 30 is provided with slots 33 and 3% and the plunger 28 has a pin 35 extending into the slots, the pin 35 serving to limit the movement of the reciprocatory plunger in both directions and also serving to prevent the plunger from rotating relatively to the sleeve 30. At the lower end of the plunger 28 at the left hand side of the detent 29 (Fig. 7 is provided a cam 36 by which the plunger is'adapted to be forced upwardly until the detent 29- clears the shoulder 25. 7

My preferred mechanism for retracting the plunger 28 comprises a sleeve 37 rotatably mounted upon the shaft 10, the sleeve having an outwardly extending flange 38 rollers 39. a0, 41', 412, 43, it and 4e5, these rollers being rotatably mounted on pins extending from the 'l'ange 38 in parallelism with the shaft 10. "The rollers 39. etc, are so positioned on the sleeve 37 that they en gage the cam 36 and forcethe plunger 28 upwardly when the sleeve 37 is rotated about the shaft 10. The outer face of the flange 38 is provided with a plurality of ratchet teeth 16, 47, etc, adapted to cooperate with a pawl 48 for stepping the sleeve 37 around in a clock-wise direction (Fig. 4A and a spring catch 4:9 is provided to hold the sleeve 37 in advanced position. 'i'he rollers 39. etc, and ratchet teeth 46, etc, are equally spaced about the sleeve o and are so related to each other that a roller engages the plunger 28 at the outset of each through a slot intermittent advancement of the sleeve 37. The pawl d8 is pivotally mounted on the outer end of an arm 50 which is rotatably mounted at its inner end upon the shaft 10, a spring 51 being provided to urge the pawl against the ratchet teeth; The pawl 48 is actuated lby a link 52 connected to the outer 52 and 53 being pivotally connected together by means of a pin 54: and the link 53 being rigidly connected to the arm 50 by;

means of a pin 55. The pin 55 extends 56 in the arm connection between the link '53 and the arm 50 may be adjusted radially with respect to the shaft 10. The lower end of link 52 is connected to the moving part 6 of the lmrchinethrough the medium of an arm 57 extending horizontally to the left of the machine as shown in Figs. 1 and 2.

The gates 8 and 9 are arranged to be raised by means of a spring-member 58 secured at its lower end to the arm 57 (Fig. 1) and being provided at its upper end with a catch 59 adapted to hook over the projection 23 on the collar 20. The member 58 also provided with a cam. face 60 immediately above the catch 59 for a purpose to be described. 7 r

The operation of the apparatus is as follows: As the lower part 6 of the machine moves downwardly away from the upper part 1 the catch 59 on finger 58 engages the projection 23 on collar 20 to swing the gates into upper horizontal position shown in dotted lines in Fig. 3. When the gates reach the upper horizontal position the shoulder 25 on disk 24 moves in behind the detent 29 on plunger 28 (Fig. 3) and locks the gates in the upper position. The catch 59 on the spring member 58 continues downwardly with the lower part 6 and slides off of the projection 23 so that the gates will drop by gravity when the deten't' 29 is withdrawn. Thus when the moving part "6 of the machine reaches its lowermost position the gates are locked in upper position by the detent 29, the catch 59 has disengaged the projection 23 and the pawl mechanism is in the position shownin Fig. a As the part 6 of the machine starts upwardly the ratchet wheel 37 is advanced by the pawl 48 in a clock-wise direction (Fig. *Ii) and oneof therollers 39, etc. engages the cam 36 on plunger 28 and retracts the detent 29 fromin front of the shoulder 25 andthe gates are permitted to fall into the lower, guarding position. As stated above the rollers 39, etc., are so positioned on the ratchet wheel 37 that one of the rollers is immediately behindthe cam 36 when the machine is open and when the partsare in the position shown in Fig. e so that the plunger 28 is forced upwardly to drop the gates as the part 6 of the machine starts upwardly and before it has advanced 50 so that the.

a substantial distance. This quick release of the gates as the moving part 6 starts upwardly is brought about in large part by the arrangement of the pawl mechanism. As shown in Fig. 4, the link 52 is almost parallel with the arm 50 so that a slight upward movement of the link 52 will produce a much larger angular movement of the pawl 48 than if the arm 50 were at approximately right angles to the link 52, the arm 50 and link 52 functioning as a toggle when thus arranged. lVhen the gates drop the disk 24 and collar 20 move into the position shown in Fig. 6 and as the moving part 6 of the machine approaches its uppermost position the cam surface on spring finger 58 engages the projection 23 on collar 20 so as to force the finger to the right (Fig. 6). When the part 6 reaches its uppermost position the catch 59 snaps over the projection 23 due to the spring action of finger 58 so that the catch 59 is in position to raise the gates when the part 6 of the machine moves downwardly.

The parts will. be in the position shown in Fig. 5 when the part 6 of the machine is moving downwardly just after detent 29 has moved into position to hold the gates open and just before part 6 reaches its lowermost position where catch 59 slides off of projection 23, the parts being in the position where catch 59 is beginning to slide off of projection 23. As shown in Fig. 6 the gates are down, the spring arm 58 carried by the part 6 of the machine is and the cam 60 is about to engage projection 23 to spring arm 58 to the right until the catch 59 has passed the projection when the elasticity of arm 58 advances the catch 59 over the projection 23.

Owing to the fact that the gates are light and are moved into closed position by gravity no harm will be done if they fall on the operators hand or arm before or as he withdraws his hand from the space between the parts 1 and 6, the gates striking his hand or arm merely serving as a warning that the machine is about to close. It will, of course, be understood that springs or weights may be provided to supplement the weight of the gates inclosing the gates.

I claim:

1. A safety appliance adapted to guard the space between the press members moving alternately together and apart in power presses and like machines, the appliance comprising a guard movably mounted so as to be moved into and out of guarding position, means for moving the guard out of guarding position, means controlled by the movement of one of said members whereby the guard is closed as the members begin to move together.

2. A safety appliance adapted to guard the space'between the press members movmoving upwardly,

ing alternately together and presses and like machines, comprising a guard movably mounted so as to be moved into and out of guarding position, means for moving the guard out of guarding position as the members move apart, and means controlled by the movement of one of said members whereby the guard is closed when the members begin to move together, the guard being so arranged as to move yieldingly into guarding position so that its movement will be decelerated upon contacting with the operator, thereby permitting the operator to withdraw before it reaches the guarding position.

3. A safety appliance adapted to guard the space between the press members moving alternately together and apart in power presses and like machines, the appliance comprising a guard movably mounted so as to be moved into and out of guarding position, means carried by one of said members for moving the guard out of guarding position as the members move apart, means for locking the guard in inoperatlve po. sition, and means for tripping the guard when the members move together, the guard being arranged to move quickly into guarding position when tripped.

4. A safety appliance adapted to guard the space between the press members moving alternately together and apart in power presses and like machines, the appliance comprising a guard mounted so as to be moved into and out of guarding position, means actuated by one of said members for moving the guard out of guarding position as the members move apart, means for looking the guard in inoperative position, and

apart in power the appliance means actuated by one of said members for tripping the guard when the parts start to move together, the guard being arranged to move quickly into guarding position when tripped.

5. A safety appliance adapted to guard the space between parts moving alternately together and apart in power presses and like machines, the appliance comprising a guard mounted so as to be moved into and out of guarding position, means actuated by one of said parts for moving the guard out of guarding position as the parts move apart, a detent for locking the guard in inoperatim position, and pawl-and-ratchet means actuated by one of said parts for retracting the detent when the parts start to move together, the guard being arranged to move quickly into guarding position when the detent is retracted.

6. A safety appliance adapted to guard the space between parts moving alternately together and apart in power presses and like machines, the appliance comprising a guard movably mounted so as to be moved into and out of guarding position, a detent 'for latching said guard out of guarding position and means actuated by one of said parts for moving the guard out of guarding position when the parts move apart and for retracting said detent when the parts start to move together, the guard being arranged to move quickly into guarding position when the detent is retracted.

7. A safety appliance adapted to guard the space between parts moving alternately together and apart in power presses and like machines, the appliance comprising a guard movably mounted so as to be moved into and out of guarding position, a detent for locking the guard out of guarding position, an actuator adapted to be attached to one of said parts in position to move the guard out of guarding position as the parts move apart and to disengage the guard when the guard'is caught by the detent, and a tripper adapted to be attached to said one part so as to retract the detent asthe parts start to move together, the guard being arranged to move quickly into guarding position when the detent is retracted.

8. A safety appliance adapted to guard the space between parts moving alternately together and apart-in power presses and like machines, the appliance comprising a guard mcvably mounted so as to be moved into and out of guarding position, means for moving the guard, means movable by one of said parts and engageable with said first means during the movement of said parts apart for moving the guard into inoperative position, a'detent for holding the guard in inoperative position, said second means moving out of engagement with said first means when the detent .picks up the guard, and means movable by one of said parts for tripping said detent as the parts start to move together.

9. A safety appliance adapted to guard the space between parts moving alternately together and apart in power presses and like machines, the appliance comprising a guard movably mounted so as to be moved into and out of guarding position, an actuator movable with one of said parts to move the guard into inoperative position as said parts move apart and to disengage the guard when the guard reaches inoperative position, a detent for holding the guard in inoperative position after the guard is disengaged by said actuator, and a tripper movable by one of said parts to retract said detent as said parts start to move together, the guard being movable into guarding position when released by the detent.

10. A safety appliance adapted to guard the space between parts moving alternately together and apart in power presses and like machines, the appliance comprising a shaft at one side of said space, a guard mounted on said shaft to swing 1nto and out of guarding position, an actuator movable by one of said parts to swing the guard into inoperativeposition as said parts move apart and to disengage the guard when the guard reaches inoperative position, a detent for holding the guard in inoperative position after the guard is disengaged by said actuator, and a tripper movable by one of said parts to retract said detent as said parts start to move together, the guard being movable into guarding position when released-by the detent. a i

11. A safety appliance adapted to'guard the space between parts moving alternately together and apart in power presses and like machines, the appliance comprising a shaft at one side of said space, a guard secured to the shaft to swing into and out of guarding position, a projection onthe shaft, an actuator movable with one of said parts to engage said projection and swing the guard into inoperativeposition as said parts move apart, the actuator being arranged to disengage said projection when the guard reaches-inoperative position, a catch on said shaft, a detent engaging said catch to hold the guard in inoperative position after said projection is disengaged by said actuator, and a tripper movable by one of 'said parts to retract said detent as said parts start tomove together, the guard being movable into guarding position when released by the detent.

12.7 A safety appliance adapted to guard the space between parts moving alternately together and apart in power presses and like machines, theappliance comprising a shaft at one side of said space, said shaft to swing into and out of guarding position, an actuator movable with one of said parts to move the guard into inoperative position as said parts move apart and to release the guard when the guardpreache's inoperative position, a detent for holding the guard in inoperative position, tably mounted on said shaft to retract said detent and permit the guard to move into guarding position, and means movable by one of said parts to actuate the tripper as said parts start to move together.

13. A. safety appliance adapted to guard the space between parts moving alternately together and apart in power presses and like machines, the appliance comprising a shaft at one side of said space, a guard secured to said shaft to swing into and out of guarding position, an actuator movable with one of said parts to move the guard intoinoperative position as said partsmove' apart :and to re leasethe guard when the guard'reaches inoperative position, a detent for holding the guard in inoperative position, a tripper rotatab-ly mounted on said shaft, the tripper having ratchet teeth and having a plurality of projections adapted successively to retract a tripper rota said detent as the tripper is stepped around, and a pawl movable with one of said parts to advance the tripper one step at a time as said parts move together, the said elements being so correlated as to trip the guard as said pa ts start to move together, the guard being movable into guarding position when released by said detent.

14. A safety appliance adapted to guard the space between parts moving alternately together and apart in power presses and like machines, the appliance comprising a shaft above said space, a guard gate fast to said shaft and adapted to swing downwardly by gravity to close said space, a projection on said shaft, a spring actuator movable with one of said parts, the actuator being arranged to engage said projection and swing said ate upwardly into inoperative position, a catch on said shaft, a detent engaging the catch when the gate is up to hold the gate in inoperative position, a tripper rotatably mounted on said shaft, the tripper having ratchet teethJand having a plurality of projections adapted successively to retract said detent as the tripper is stepped around, and a pawl movable with one of said parts to advance the tripper one step at a time as said parts move together, the said elements being so correlated as to trip the guard as said parts start to move together, the guard being movable into guarding position when released by said detent.

15. A safety appliance adapted to guard the space between parts moving alternately together and apart in power presses and like machines, the appliance comprising a guard, a catch comiected to the guard, a latch adapted to be mounted on one of said parts so as to engage said catch as said parts move apart to move the guard into inoperative position, the latch'being yielding so as to spring 011? of said catch when the gates reach inoperative position and so as to spring onto said catch when said parts move together.

16. A safety appliance adapted to guard the space between parts moving alternately together and apart in power presses and like machines, the appliance comprising a guard movably .iounted so as to be moved into and out of guarding position over said space, a detent for holding the guard out of guarding position, means for releasing said detent to permit the guard to move into guarding position, and means means with one of said parts, the connecting means being arranged to multiply the motion of said part so that a slight movement of the part will produce a relatively large movement of the releasing means.

1.7. A safety appliance adapted to guard the space between parts moving alternately together and apart in power presses and like machines, the appliance comprising a guard movably moinited so as to be moved into and out of guarding position over said space, a detent for holding the guard out of guarding position, means for releasing said detent to permit the guard to move into guarding position, and toggle means connecting said releasing means with one of said parts so that a slight movement of the part will produce a relatively large movement of the releasing means, whereby the guard is quickly released as said parts start to move together.

Signed by me at Boston, Massachusetts, this 11th day of July, 1918.

WILLIAM WOELFEL.

connecting said releasing 

